A pin configuration changing circuit of a base chip includes pin configuration changing register (PCCR) and a pin configuration changing logic unit (PCCLU). The PCCR stores and provides a pin connection assignment value indicating a first connection order of a plurality of pins included in a memory connected to the base chip, based on a type of the memory when the memory is changed. The PCCLU receives the pin connection assignment value and changes a second connection order of a plurality of inner pins of the base chip. Various memories can be connected to the base chip without extra wiring or a printed circuit board (PCB).